Crusade: Starfire, Book 1

Spacers call the warp point Charon's Ferry. No star ship has ever entered it and returned since a vengeful Orion task force pursued a doomed Terran colonization fleet into it in 2206. Almost a century has passed. The fiery hatreds of a quarter-century of warfare between the Terran Federation and the Zheeerlikou'valkhannaieeee, the cat-like species humans called the "Orions", have eased at least a little.

In Death Ground: Starfire, Book 3

Five thousand years after Sun Tzu writes The Art of War, his advice is followed during the Fourth Interstellar War between the terrible Bugs and the humans, who are aided by their catlike Orion allies.

The Shiva Option: Starfire, Book 4

The mind-numbingly alien Arachnids were an enemy whose like no civilized race had ever confronted. Like some carnivorous cancer, the "Bugs" had overrun planet after planet...and they regarded any competing sentient species as only one more protein source. They couldn't be reasoned with, or even talked to, because no one had the least idea of how to communicate with a telepathic species with no recognizable language...and whose response to any communication attempt was a missile salvo.

Insurrection: Starfire, Book 2

In the end, the only political systems that seem to work are those based on freedom. The Inner World leaders of the Terran Federation seem to have forgotten this simple truth. After fighting the Khanate - with the Fringe Worlds to supply the raw material and the fighting men - the Inner Worlds found it hard to give up the powers they had seized during the war.

Exodus: Starfire, Book 5

Long ago, much of the population of an entire planet fled their world before its sun went nova in thousands of ships, each one larger than a city. Now, the armada has arrived at the world they intend to make their new home. They regard the fact that the planet is already colonized by humans as a mere inconvenience, and their mode of communication is so different from anything humans use that they do not consider humans and their allies to be truly intelligent.

Extremis: Starfire, Book 6

An implacable foe with telepathic cohesion in battle, near immortality, and eons-advanced engineering skills threatens to wipe humanity from the galaxy. What's more, they've overcome their one weakness - no faster-than-light travel - and have followed humanity through our star gates and beyond. But humans are the master of adaption and have got a counterpunch of devastating proportions in reserve.

now for the one

very solid story with a nice concept. if you liked the others you will like this

Imperative: Starfire, Book 7

The war with the Arduans - profoundly alien invaders who originally arrived in STL ships - is over. Most of those attackers are now probationary (and very productive) citizens of the Rim Federation. However, many among the Arduans' warrior caste have accepted neither defeat nor the personhood of any of the other intelligence races. Their leader, the ruthless admiral of the second Arduan exodus, Amunsit, is in firm control of the Zarzuela system.